Milenkaya O, Legge S, Walters J R
Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061; 2Australian Wildlife Conservancy, Mornington Wildlife Sanctuary, Derby, Australia; and Research Institute for Environment and Livelihoods, Charles Darwin University, Casuarina, Australia.
Physiol Biochem Zool. 2014 Jul-Aug;87(4):550-8. doi: 10.1086/676651. Epub 2014 May 29.
Abstract It is common in evolutionary ecology to interpret body-condition indices as indicators of individual quality, but this hypothesized relationship has been questioned and remains poorly validated. Here, we test one of the fundamental predictions of this condition-quality hypothesis, that relative-condition indices are repeatable within individuals, that is, that the index score of an individual relative to others is consistent over time. We sampled crimson finches (Neochmia phaeton) for seven commonly used condition indices and tested whether individual condition relative to conspecifics in the same context (e.g., breeding stage) was repeatable. We calculated the relative indices' repeatability across several temporal scales, from short (within breeding season) to long (more than 2 yr) time periods, as well as without consideration of timescale. Most relative-condition indices were repeatable when sampled without consideration of timescale, all were repeatable within a short time period, and none were repeatable over the longest time period. This provides only partial support for the condition-quality hypothesis, because although relative-condition indices were generally repeatable, this was primarily attributed to short-term, instead of long-term, repeatability. Condition indices may be meaningful indicators of short-term survival or fitness potential, but our findings are inconsistent with the idea that condition indices are indicators of inherent individual quality.
摘要 在进化生态学中，将身体状况指数解释为个体质量的指标很常见，但这种假设的关系受到了质疑，且仍未得到充分验证。在此，我们检验了这种状况 - 质量假设的一个基本预测，即相对状况指数在个体内部是可重复的，也就是说，个体相对于其他个体的指数得分随时间是一致的。我们对朱红雀（Neochmia phaeton）进行采样，测量了七个常用的状况指数，并测试了在相同背景下（例如繁殖阶段）相对于同种个体的个体状况是否可重复。我们计算了相对指数在几个时间尺度上的可重复性，从短时间尺度（繁殖季节内）到长时间尺度（超过两年），以及不考虑时间尺度的情况。在不考虑时间尺度进行采样时，大多数相对状况指数是可重复的，在短时间内所有指数都是可重复的，而在最长时间尺度上没有一个指数是可重复的。这只为状况 - 质量假设提供了部分支持，因为尽管相对状况指数通常是可重复的，但这主要归因于短期而非长期的可重复性。状况指数可能是短期生存或适应潜力的有意义指标，但我们的研究结果与状况指数是固有个体质量指标的观点不一致。
